def create_transaction(node, coinbase, to_address, amount, expiry_height):
from_txid = node.getblock(coinbase)['tx'][0]
inputs = [{"txid": from_txid, "vout": 0}]
outputs = {to_address: amount}
rawtx = node.createrawtransaction(inputs, outputs)
tx = CTransaction()
# Set the expiry height
f = cStringIO.StringIO(unhexlify(rawtx))
tx.deserialize(f)
tx.nExpiryHeight = expiry_height
rawtx = hexlify(tx.serialize())
signresult = node.signrawtransaction(rawtx)
f = cStringIO.StringIO(unhexlify(signresult['hex']))
tx.deserialize(f)
tx.rehash()
return tx